I'd encourage you to broaden your understanding of the purpose of PoW and specifically the energy used. The energy used is the cost of securing a PoW blockchain--quite literally, the cost of the energy used is what makes it difficult to mount a successful attack. It is simple and universally accessible. It is not "inefficient"; it is functioning exactly as intended.
What I think you are really trying to say is that you think the benefits provided by a PoW blockchain do not merit the economic expense of securely maintaining it. And that's a fine opinion to have. But the only reason you pay attention to the electricity cost is because it is highly visible--you probably have no clue how much electricity is consumed by all the other economic activities that you may consider pointless or wasteful.